We propose to use our present 5-bed Stroke Unit to perform protocol evaluations of patients with transient ischemic attacks or established strokes with minor residua preoperatively and at stated dates after carotid endarterectomy or transcranial anastomosis of superficial temporal to cortical arterial branches. Evaluation will include standard history, physical examination, routine laboratory work and 4-vessel angiography plus measures of cerebral blood flow. Comparison of methods, looking toward the development of reliable non-invasive techniques for measuring blood-flow, will be made. The research described will be used as the basis for the intensive education of medical students, house-staff, fellows, practitioners and nurses in the modern diagnosis and treatment of stroke.